Filter module

ABSTRACT

The invention relates to a filter module for removing air-polluting materials from machine exhaust, comprising a filter housing with an intake opening and an outlet opening for channeling machine exhaust through, at least one mounting element for mounting the filter module on a machine, and a filter assembly, arranged in the filter housing and comprised of at least two filter groups, arranged in tandem in the direction of flow and comprised of rod-shaped filter elements with a filter medium, said elements being arranged parallel to one another at a constant center-to-center distance and with their longitudinal axis largely crosswise to the direction of flow, wherein the filter elements of two adjacent filter groups are parallel to one another, and are arranged offset in relation to one another, crosswise to their longitudinal axes and to the direction of flow. The filter elements are connected with at least one filter bracket to form at least one filter insert, and the filter insert is detachably connected to the filter housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of and claims the benefit ofpriority of International Patent Application No. PCT/AT2005/000359,filed on Sep. 9, 2005, which is relied on and incorporated herein byreference.

BACKGROUND OF THE INVENTION

The invention relates to a filter module for removing air-pollutingmaterials from machine exhaust, comprising a filter housing with anintake opening and an outlet opening for channeling machine exhaustthrough, at least one mounting element for mounting the filter module ona machine, and a filter assembly, arranged in the filter housing andcomprised of at least two filter groups, arranged in tandem in thedirection of flow and comprised of rod-shaped filter elements with afilter medium, said elements being arranged parallel to one another at aconstant center-to-center distance and with their longitudinal axislargely crosswise to the direction of flow, wherein the filter elementsof two adjacent filter groups are parallel to one another, and arearranged offset in relation to one another, crosswise to theirlongitudinal axes and to the direction of flow.

From U.S. Pat. No. 6,726,749 B2, a filter device of this type designedfor removing air-polluting materials from the exhaust air from machines,especially office machines, is known. This device has a plurality offilter sticks in a filter housing, which sticks are supplied with fluidfrom a fluid container, and a fastening device for mounting the filterhousing on a machine, wherein the filter rods are positioned in theexhaust air flow. As can be seen in FIG. 7 of the US publication, in oneembodiment the filter rods are arranged in rows, and the rows are offsetin relation to one another. The air-polluting materials are adsorbed asthey pass by the filter rods wetted with the fluid, and are therebyremoved from the exhaust air flow.

The disadvantage of this system is that each of the filter rods ismounted separately in the filter housing, so that maintenance orreplacement of the filter rods is correspondingly laborious and tedious.Also disadvantageous is that the fluid is consumed when the filterdevice is in use, and the fluid container must be regularly refilled toextend its useful period, to maintain the wetting of the filter rods.This filling process requires a great deal of caution or additionalaccessories to prevent contamination. Independent of the supply withfluid, if the filter rods are badly soiled following an extended periodof use or due to severely polluted machine exhaust, a reconditioningcleaning or replacement of the filter rods or of the entire filterdevice may be necessary, which, because of the individually attachedfilter rods, entails high costs from increased handling expenses or acomplete replacement.

The object of the invention consists in providing a filter device of thedescribed type that is characterized by a more simplified applicationand entails only low costs in its production and use.

The object of the invention is attained with a filter module forremoving air-polluting materials from machine exhaust, comprising atleast two parallel filter groups, arranged in an offset from one anotherin the direction of flow of exhaust, wherein each filter group includesa plurality of spaced-apart rod-shaped filter elements, and wherein atleast two or more spaced-apart rod-shaped filter elements of at leastone filter group are connected as a filter insert detachably coupling toa filter housing.

One advantage of the filter module of the invention is the combinationof the filter elements with at least one filter bracket to create atleast one filter insert, which can be removed from the filter housing.This allows the filter insert to be handled separately from the filterhousing, for example in order to more easily clean the filter elementsor the filter medium, to replace individual filter elements, or toexchange the entire filter insert. The filter bracket can be astrip-type element, to which the individual filter elements areattached, preferably orthogonally, parallel to one another, and at aconstant center-to-center distance; the bracket may also beframe-shaped, for example, fastening both ends of the individual filterelements. The filter medium can be situated both on the outer surface ofthe filter elements and on the interior of the filter elements if thefilter medium is capable of coming into contact with the exhaust airthrough openings in the surface of the filter elements, for example ifthe filter element is cage-like in structure.

A further advantageous effect is achieved with a configuration involvingmultiple filter inserts, especially if multiple rows of filter elements,preferably the individual filter groups, each with its own filterbracket, are combined. This allows the individual filter rows or filtergroups to be cleaned or replaced independently of one another, basedupon the degree of soiling, thereby reducing the cost of exchanging thefilter inserts, since filter inserts that are still usable can continueto be used.

According to another embodiment of the filter module of the invention,offsetting the filter elements of two filter groups, which are arrangedin tandem in the direction of flow, by half the center-to-centerdistance causes maximum redirection of the exhaust air as it passes bythe filter elements, thereby improving the removal rate of the filtermodule.

The formation of a slide-in opening for the filter inserts in the filterhousing enables more direct and better access to the individual filterinserts than through the intake opening or the outlet opening, sincethese permit only sequential access to the individual filter inserts.However, the slide-in opening can also be formed by a series ofopenings, through which the individual filter elements project into theinterior of the filter housing, while the filter bracket remains outsideof the filter housing.

According to a further improvement, for a secure positioning of thefilter inserts in the filter housing it is advantageous to provide guideelements for securing the assembled position. These can be provided inthe form of a longitudinal guide, along which the filter inserts areinserted into the filter housing, or in the form of localized guideelements, which come into force shortly before the proper slide-inposition is reached.

One advantageous option for situating a filter insert in the installedposition consists, according to a further embodiment, in configuring theslide-in opening as a guide element, wherein said element accommodatesthe filter bracket with a low level of play, which causes the installedfilter insert to be secured crosswise to the slide-in direction. It isalso possible to provide a separate slide-in opening for each filterinsert, or to position the filter inserts snugly against one anotherthrough one common slide-in opening.

According to a further embodiment, an additional guide elementconfiguration can be formed by a recess or opening in the filter housingopposite the slide-in opening, into which one or more filter elements ora frame-type filter bracket extend. Said recess can be limited to thehousing wall alone, or can also be formed by a sleeve-like seatingelement that projects into the interior of the filter housing andaccommodates an end section of the filter elements or the filter insert.

To achieve the offset between the filter elements of filter rowsarranged in tandem, it is advantageous to offset the guide elements forthe individual filter inserts in relation to one another. In thismanner, the redirection of the exhaust air flow necessary to produce thecleaning effect is ensured.

For reasons of economic efficiency and user-friendliness it also makessense, according to a further dependent claim, to configure the filterinserts that form a filter assembly to be structurally uniform. Thismakes manufacturing more cost-effective due to the larger number ofpieces, and makes storage more cost-effective, while reducing thepossibility of confusion for the user.

A further increase in user-friendliness can be achieved, according to afurther characterizing feature, through a symmetrical configuration ofthe filter inserts. The more planes of symmetry a filter insert has, thelower the risk of inserting these incorrectly into the filter housing,allowing filter replacement to be performed without difficulty even bytechnical laypeople. The offset between the individual filter inserts inthe embodiments having two or three planes of symmetry is effected byoffsetting the guide elements and/or the slide-in openings.

According to a further embodiment, configuring the filter elements tohave a large effective cross-section (in other words within a filtergroup the area of the filter elements that is projected in a planeperpendicular to the direction of flow is larger than the free passagearea between the filter elements, which is projected in a planeperpendicular to the direction of flow) causes a sharp redirection whencombined with the offset between the filter rows arranged in tandem, andthe air-polluting materials contained in the exhaust air are adsorbed ata high level of probability. A further increase in the removal rate canbe achieved by arranging more than two filter inserts in tandem, ormultiple filter modules in tandem, although this will also increase flowresistance, which is permissible to only a limited extent, in order toavoid any unacceptable interference with the removal of heat from themachine producing the exhaust.

One possibility for reducing the costs of the filter inserts, accordingto a further dependent claim, consists in detachably connecting thefilter elements to the filter bracket, which allows individual filterelements to also be replaced. Especially if the individual filterelements are loaded at different levels with the air-polluting materialsor dust particles due to flow conditions, a replacement of individualfilter elements can be advantageous. The filter elements can also beremoved separately, which with certain embodiments of the filterelements (for example those having a star-shaped cross-section) orfilter inserts can facilitate cleaning.

According to a further embodiment, it is advantageous for the filterelements to be attached to the filter bracket by means of a press fit,so that no additional means of attachment are necessary.

According to a described embodiment of the filter module, selecting thematerial for the filter medium from the group comprised of porousmaterial, fibrous mesh, pulp material or a plastic foam is beneficialfor positively influencing the removal rate of the filter module. On onehand, the pores and fibrous components in these materials act assupplementary mechanical collection surfaces, while on the other handthese materials can also serve as a storage medium for a chemicallyand/or physically active fluid, which adsorbs or absorbs theair-polluting materials. The porous material can be formed, for example,from a ceramic or metallic foam, which have a high level of mechanicalstability and therefore are not prone to damage during assembly orcleaning. The fibrous mesh made of inorganic or organic and naturalfibers, such as cellulose, cellulose acetate, polyester, etc., is alsocharacterized by a high filtering effect. Plastic foams or latex foamcan also be used as the filter medium, especially open-celled materialslike PU foam, which is widely used as a wet-filter medium. For certainpurposes, several different filter media can also be used in a filterassembly, to combine their respective advantageous properties.

By forming the filter elements from the same material as the filtermedium, the filter volume can be substantially increased, allowing theservice life of the filter inserts to be extended or the storage volumefor fluid to be increased. Furthermore, the reduction in the number ofmaterials used can decrease the cost of manufacturing the filterelements.

It can also be of benefit with certain embodiments to configure thefilter medium and the filter element as a single piece, especially ifthe filter medium is sufficiently strong to withstand without damage theforces that occur during assembly and handling of the filter inserts,for example if the filter medium is sufficiently compressed. With theproper material selection, this can also serve to reduce manufacturingcosts.

In a further embodiment of the filter module, the filter medium isprovided on only a partial section of each filter element. Thus it ispossible, for example, to provide the filter medium in a material-savingfashion only on the side of the filter elements that receives the flow.The expansion of the filter medium can also be limited to a sectioninside the filter element. In particular, the ends of the filterelements can be structured without filter medium, in order to facilitateattachment on the filter bracket or in the filter housing via a socketconnection.

According to a further embodiment, providing the filter medium on thesurface of the filter elements opens up a wide range of designpossibilities for the shape of the supporting filter elements, andoffers good accessibility if the filter elements should requirecleaning. With the mentioned filter media it is somewhat difficult toproduce complicated cross-sectional shapes, which is why in these casesa subsequent application on the surface of the filter elements is easierto produce. The connection between the filter medium and the filterelements can be mechanical, for example a clamping or spanning of thefilter medium, and may involve a separate layer of adhesive orapplication of the filter medium in an adhesive state, for example byfoaming the filter elements with a material that in its hardened statewill form the filter medium.

According to a further embodiment, an improvement in the filteringeffect of the filter module can be achieved by wetting the filter mediumwith a fluid selected from the group of fluids glycerin, silicone oil,essential oil, paraffin oil, and/or latex emulsion. The air-pollutingmaterials in the machine exhaust, such as dust, fine dust, ultrafineparticles, pollen, spores, bacteria, other aerosols with solid or liquidparticles, and in the case of an office machine especially toner dustand/or paper wear debris, can be effectively bonded mechanically whenthey come in contact with the wetted filter medium, and gaseouspollutants, such as ozone, benzole, phenol, carbon dioxide, formaldehydeor unpleasant odors can also be chemically absorbed and/or neutralizedby coming into contact with the fluid. One advantageous effect of thesecomponents consists in their low vapor pressure and correspondingly lowevaporation rate, which produces a long service life. The viscosity ofthese fluids is further favorable to an even distribution in the filtermedium via the capillary effect that occurs with the wetting of thefilter medium. With a correspondingly adjusted high level of viscosityand surface tension, a direct wetting of the filter element is alsopossible, whereby the filter medium is formed by the fluid.

A further possible embodiment of the filter module consists in adding anolfactory substance to the fluid, allowing the air flowing out of thefilter module to release a pleasant scent. By properly adjusting theconcentration and the evaporation rate of the olfactory substance, theduration of scent release can be adjusted to the service life of thefluid, with the fading of the scent over time serving as an indicator ofthe need to change the filter elements or replace the fluid.

According to a further embodiment, it is also advantageous to add anantibacterial, antiviral, antimycotic or fungicidal substance to thefluid, whereby, on one hand, bacteria or mold spores emitted by themachine are rendered harmless when they come into contact with thefluid, and on the other hand the concentration or colonization of thefilter elements with bacteria, viruses or fungi is prevented.

To prevent harm to the environment in the cleaning or disposal of thefilter medium and/or filter elements that are wetted with the fluid, itis possible, according to one dependent claim, to use a wetting fluidthat is readily biodegradable. The biochemical acid requirement forbiological degradation in waste water (e.g. BSB5 value) and the WaterHazard Classification should be as low as possible.

Further, according to another embodiment of the filter module it isadvantageous to equip the filter medium with an antibacterial surface.This can be accomplished, for example, with a coating or impregnationwith silver, especially nanoscale silver, or a silver compound.

According to a further embodiment, it is advantageous to store the fluidwithin hollow spaces inside the filter elements, and to deliver itslowly to the filter medium via openings, such as small bore holes orslits. In this manner, fluid losses in the filter medium fromevaporation can be continuously compensated for, and the service life ofthe filter elements can be extended.

A possible further improvement consists in forming at least a part ofthe filter medium from activated carbon, which is characterized by ahigh capacity for adsorbing polluting gases and odors. When combinedwith scent-releasing filter elements, the filter elements with activatedcarbon components in the filter medium should therefore be arranged infront of the scent-releasing filter elements, viewed in the direction offlow.

To remove ferromagnetic particles, such as iron wear debris, from themachine, one embodiment provides that one or more filter elements beequipped with a magnetic element or a magnetic component. This can be apermanent magnet or an electromagnet.

A further embodiment of the filter module is characterized by the factthat the rod-shaped filter elements have an elongate cross-section, inother words a cross-section with a prominent longitudinal axis. Thisincreases the ratio of surface to volume of the filter elements,allowing a large filter surface to be accommodated in a relatively smallamount of space.

According to a further embodiment, it is also advantageous to orient thelongitudinal axes of the cross-sections crosswise to the direction offlow, in order to create large active surfaces and a sharp redirectionof the exhaust air. With this arrangement of the filter elements, thefilter module can be configured to be short, viewed in the direction offlow, with multiple filter inserts in tandem.

According to a further embodiment of the filter module, thecross-section of the filter elements can be rectangular, triangular,star-shaped or round in configuration. The rectangular, triangular orround, especially circular, embodiment of the filter elements is easy toproduce in terms of manufacturing technology; the rectangular andcircular cylindrical forms also favor a symmetrical configuration of thefilter inserts. The star-shaped cross-section, in contrast, offers ahigh value in the ratio of surface to volume of the filter element,allowing a large filter surface to be accommodated in a relatively smallspace. The cross-sectional shape can also be used to influence the flowof exhaust air through the filter assembly, for example to eddy the flowthrough cross-sections that are unfavorable to flow, such as rectangularcross-sections, and to intensify contact of the exhaust air with thefilter medium, or to calm the flow through cross-sections that arefavorable to flow, such as triangular cross-sections, if the exhaust airflow from the machine is strong and turbulent and therefore potentiallydisruptive.

The mounting element for attaching the filter module to the machineemitting exhaust air can be advantageously comprised of a layer ofadhesive, an adhesive strip, a Velcro strip, a screw, a locking pin, ora snap connector, wherein these fastening options are listed only asexamples, and other fastening means can also be used. A Velcroconnection between the filter housing and the machine especiallyprovides easy assembly and handling by the user. The internal connectionbetween the hook tape and the loop tape of the Velcro strip also acts asa seal between the machine and the filter housing, so that the exhaustair flow is guided largely through the filter module. However, aseparate sealing element, such as a self-adhering sponge rubber strip,can also be used as a seal.

It is advantageous to position the mounting element in the area of theintake opening to the filter housing, in order to achieve small andcost-effective mounting components, and to make the attachment visuallyinconspicuous.

A further advantageous option for mounting the filter module is achievedby forming a groove on the rear side of the filter housing that facesthe machine, into which an interconnecting element having an angularprofile is inserted, and in that the interconnecting element is attachedto the machine by means of the mounting element, preferably a Velcrostrip.

According to a further, it is also advantageous to equip the filterhousing with one or more connecting elements for connecting it toadditional filter modules. Although it is naturally possible to adjustthe size of a filter module to the exhaust air opening of the machine,in general it is more cost-effective to produce the filter modules in auniform size and then assemble a filter device of the proper size byconnecting multiple filter modules. Due to the many different types andsizes of machines in which the filter modules can be used, individualassembly from a standard size is more practical than a multitude ofspecial production runs.

According to a further embodiment, the connection between two filtermodules can be formed by a locking pin, a mounting rail or mountinggroove, a dovetail connection, or a Velcro strip. However, any othertypes of connections, such as adhesives, screws, clamps, snapconnections, etc., may also be used.

According to a further embodiment, in which the edges of two boundarywalls of two filter housings are encompassed by a clamp element, canadvantageously be implemented on the front side and/or the rear side ofthe filter housing. The clamp element is configured, for example, as aU-profile, which, when applied, achieves the clamping effect via a pressfit.

For easier handling of the filter inserts it is further advantageous forthe filter insert to have a handle element on the filter bracket, withwhich a user can grasp the filter insert when it is installed.

According to a further embodiment, producing the components of a filtermodule, especially of the filter housing, the filter bracket and/or thefilter element, using a plastic injection molding process is economicalespecially when large piece numbers are required, and achievesconsistently high workpiece precision levels and quality. In selectingthe plastic to be used, the temperature of the exhaust air must be takeninto account, so that during use, no impermissible shape changes in thecomponents of the filter module occur as a result of the exhaust airtemperatures.

An easily producible configuration of the separable connection betweenthe filter insert and the filter housing consists, according to afurther claim, in providing a non-positive snap connection, especiallywith a spherical locking projection that engages in a locking recess.

According to a further embodiment, the filter module can be equipped atthe outlet opening, in other words at the visible front side, with acovering grid plate. This offers protection against unintended contactwith the filter elements, especially if these are wetted with fluid,while also offering visual design possibilities for the front side ofthe filter module. With a lamellar configuration of the grate rods, theflow of the exiting, filtered air can also be influenced, for exampledeflecting it in a specific direction. For attaching the covering gridplate, all possible types of attachment, such as screws, clamps,adhesives, etc, are again possible.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings show:

FIG. 1 a perspective illustration of a filter module with a partiallyremoved filter insert;

FIG. 2 a simplified representation of a filter module in verticalsection along the line II-II in FIG. 3;

FIG. 3 a horizontal section of two embodiments of the filter module,sectioned along the line III-III in FIG. 2, in a simplified, sectionalrepresentation;

FIG. 4 a simplified, sectional representation of several embodiments ofthe separable connection between a filter insert and a filter housing;

FIG. 5 embodiments of filter inserts with one, two and three planes ofsymmetry, in a simplified representation, each from a front view and aplan view;

FIG. 6 two embodiments of a filter element in a simplified, perspectiverepresentation;

FIG. 7 two additional embodiments of a filter element in a simplified,perspective representation;

FIG. 8 an embodiment of the connection between two filter modules in asimplified, sectional representation.

DETAILED DESCRIPTION OF THE INVENTION

By way of introduction, it is noted that in the differently describedembodiments, equivalent parts are designated by the same referencesymbols or component descriptions, wherein the disclosures contained inthe entire description can be logically transferred to equivalent partshaving the same reference symbols or the same component descriptions.Also, positional information selected in the description, such as above,below, to the side, etc., refers to the immediately described orillustrated figure, and, in the case of a position change, can belogically transferred to the new position. Furthermore, individualcharacterizing features or combinations of features from the illustratedand described exemplary embodiments can also represent solutions thatare independent, inventive or specified in the invention.

FIG. 1 shows an embodiment of a filter module 1 according to theinvention for removing air-polluting materials from machine exhaust. Theexhaust air can come from a multitude of different machines, with animportant area of application for the filter module 1 of the inventionbeing machines that emit exhaust air in enclosed spaces in which peoplemay be found. This applies especially to office machines such ascopiers, printers or fax machines, which are used widely and frequently.The air-polluting materials to be removed or filtered include dust, finedust, ultrafine particles, pollen, spores, microorganisms, such asbacteria, and other aerosols containing solid or liquid particles, andin the case of an office machine especially toner dust or paper weardebris, and gaseous contaminants, such as ozone, benzole, phenol,solvents from printer inks and tints, carbon dioxide, formaldehyde, orunpleasant odors.

The following additional areas of application of the filter module ofthe invention are listed as examples of the multitude of potentialapplications: installation in or on the outlet of exhaust pipes orchimneys, use as a back-up filter or supplementary filter for vacuumcleaners, use in motor vehicles, for example as a supplementary airfilter or as a filter for the air in the interior of the vehicle, forexample as a pollen filter, as an industrial filter in power plants,filters for indoor air systems, such as air conditioners or ventilationsystems. Express reference is made in this connection to the possibleuse as a filter for supplied air, ambient air, or intake air for thewidest range of machine types.

The body of the filter module 1 is formed by a filter housing 2, whichis configured to channel exhaust air from a machine through it. Theexhaust air flow or the direction of flow 3 of the exhaust air isindicated by an arrow 3. In the embodiment shown, the filter housing 2is configured as a rectangular frame with four boundary walls 4, but mayalso have a different, for example circular, cross-section, viewed inthe direction of flow 3, as well as a larger extension, making ittubular in configuration. Furthermore, the cross-section in thedirection of flow 3 can be either consistent or adjustable. The exhaustair flows through an intake opening 5 to an outlet opening 6 in thefilter housing 2, with these offering the largest possible opencross-section for low-loss channeling.

The exhaust air is filtered through a filter assembly 7 arranged in theinterior of the filter housing 2, which is comprised of at least twofilter groups 8 arranged in tandem in the direction of flow 3. Eachfilter group 8 is comprised of multiple rod-shaped filter elements 10,which are arranged with their longitudinal axes largely crosswise to thedirection of flow 3 and which are parallel to one another at aconsistent center-to-center distance. The filter elements 10 of at leasttwo adjacent filter groups 8 are also parallel to one another. With morethan two filter groups 8 in a filter assembly 7, one or more filtergroups 8 can also have filter elements 10 with orientations that differfrom the two adjacent and parallel filter groups 8.

Regardless of this separation into tandem filter groups 8, in each casemultiple filter elements 10 are combined with a filter bracket 11 toform a filter insert 12. In the embodiment represented in the figure, afilter insert 12 is a largely flat structure, with the surface orientedperpendicular to the direction of flow 3. The individual filter elements10 are rod-shaped with a rectangular cross-section, with the longer sideof the rectangle being oriented crosswise to the direction of flow 3. Asan alternative to this strip-type configuration, other forms with whichespecially the effects presented in the introduction to the descriptioncan be achieved, such as square, triangular, star-shaped, circularcylindrical or oval cross-sections, are also possible.

The filter brackets 11 create a connection of multiple filter elements10, wherein in the illustrated embodiment those filter elements 10 thatare arranged within a plane perpendicular to the direction of flow 3 arejoined, so that precisely one filter group 8 is contained in one filterinsert 12. The filter elements 10 of a filter assembly 7 can, however,be joined in the widest variety of ways by altering the configuration ofthe filter brackets 11, for example by orienting the strip-type filterbrackets 11 in the direction of flow 3 so that they join filter elements10 from different filter groups 8 to one another. It is also possiblefor all filter elements to be joined by one filter bracket 11, so thatthe filter assembly 7 is formed by only one filter insert 12.

The filter elements 10 from two filter groups 8 arranged in tandem arenot arranged in tandem in a straight line viewed in the direction offlow 3, but are offset, parallel to one another, crosswise to thedirection of flow 3. In the exemplary embodiment shown in FIG. 1, twostructurally uniform filter inserts 12 are arranged in the filterhousing 2, offset in relation to one another by half thecenter-to-center distance 9, whereby filter elements 10 situated intandem are also offset in relation to one another, and in each case, afilter element 10 of an adjacent filter group 8 is centered behind a gapformed by two adjacent filter elements 10 of a filter group 8. If thewidth of the filter elements 10 is greater than half thecenter-to-center distance 9, as in the illustrated example, it isimpossible to pass by the filter assembly 7 in a straight line, whichforces a sharp redirection of the exhaust air flowing through, therebyincreasing the filtering effect.

With the proper dimensions, the filter inserts 12 can be insertedaxially into the filter housing 2 through the intake opening 5 and/orthe outlet opening 6, relative to the direction of flow, however it ispractical, as shown in the exemplary embodiment, to provide a separateslide-in opening 13 in the filter housing 2 for the filter insert orinserts 12. The slide-in opening 13 is configured such that twobordering filter brackets 11 that are offset in relation to one anothercan be accommodated with a low level of play. Alternatively, a separateslide-in opening 13 can be provided for each filter insert 12, leaving agreater distance between filter groups 8 arranged in tandem. At the sametime, the slide-in opening 13 forms a guide element 14 by accommodatingthe filter inserts 12 in the installed state with a low level of play,thereby securing their position.

Additional guide elements 14 are formed by recesses 15 in the filterhousing 2 into which the unattached ends of the filter elements 10engage when installed. In many cases, however, the guidance provided bythe securing of the filter bracket 11 in the slide-in opening 13 issufficient.

To connect multiple filter modules 1, this module has multipleconnecting elements 16 on the boundary walls 4, which permit a simpleassembly of larger filter devices from individual filter modules 1. InFIG. 1, by way of example, two types of connecting elements 16 areshown, wherein on one filter module 1, different or only the sameconnecting elements 16 may be used. In each case a vertically orienteddovetail rail 17 and a dovetail groove 18 are arranged on the verticalboundary walls 4, and can be used to connect filter modules 1 in ahorizontal direction.

For expansion in a vertical direction, 4 bore holes 19 are situated onthe horizontal boundary walls 4, into which fastening pins (not shownhere) can be inserted, and a connection of filter modules 1 in avertical direction can be produced.

In FIG. 2, a filter module 1 is shown in vertical cross-section, inwhich a filter insert 12 inserted into the filter housing 2 is visible.A filter medium 20 is arranged on the filter elements 10 lying in theexhaust air flow, as indicated by a section of cross-hatching. Thefilter medium 20 is a porous material, which contains hollow spacesand/or capillaries in its interior, and can be impregnated with a fluid.The fluid is a silicone oil type AK 2000 from the Wacker Chemie firm,but can be replaced by any fluids listed in the introduction to thedescription. With the pores that are contained, the active surface ofthe filter medium 20 is greatly enlarged over that of a smooth surface,while at the same time the pores form the volume necessary for storingthe fluid. In the exemplary embodiment, the filter medium 20 iscomprised of polyester fibers, which are pressed into a fibrouscomposite. Filter media of this and similar types are available, forexample, from the Filtrona firm. Of course, other materials can also beused to construct the filter medium 20. The strength of this compositemakes it possible to construct the filter element 10 in its entiretyfrom the material of the filter medium 20. The filter element 10 and thefilter medium 20 are therefore cost-effectively configured as a singlepiece. The filter elements 10 are attached to the filter bracket 11 viaa press fit, and can be exchanged by simply pulling them out andinserting others.

To make it easier to grasp a filter insert 12 when removing it from thefilter housing 2, each filter insert is equipped with a handle element21.

FIG. 3 shows two exemplary embodiments of the filter module, inhorizontal cross-section. In each case a filter module 1 is fastened toa machine housing 22, specifically such that the intake opening 5 of thefilter housing 2 is positioned in the extension of the exhaust airopenings 23 of the machine. To achieve this, the filter housing 2 isattached via a mounting element 24 to the machine housing 22. Themounting element 24 in the exemplary embodiment is comprised of a Velcrostrip with a coordinating loop tape and hook tape, wherein the hook tapeis attached to the filter housing 2, for example via adhesive, and theloop tape is attached to the machine housing 22, or vice versa. In FIG.3 a, the mounting element 24 is arranged directly on the boundary wall4, whereas in FIG. 3 b the mounting element 24 is arranged on anangular-profiled interconnecting element 25. This element is situated onthe rear side of the filter housing 2, facing the machine, in a groove26, and enables an adjustment of the distance between the filter module1 and the machine housing 22 by shifting a leg of the interconnectingelement 25 in the groove 26. The interconnecting element 25 has agreater degree of flexibility than the entire filter module 1 and cantherefore more easily adjust to uneven areas of the machine housing 22,enabling it to be mounted even on uneven machine housings 22. At thesame time, the interconnecting element 25 prevents the exhaust air fromescaping laterally between the machine housing 22 and the filter module.

A covering grid plate 27 is fastened over the outlet opening 6 of thefilter housing 2, protecting the filter elements against unintendedcontact, while the configuration of the grid elements 28 [sic] makes itpossible to influence the exhaust air flow.

In FIGS. 4 a through 4 f, various examples for connecting the filterbracket 11 or the filter insert 12 to the filter housing 2 or to anupper boundary wall 4 are shown.

FIG. 4 a shows a link plate 28 that overlaps two adjacent edges of thefilter housing 2 and the filter bracket 11, and is separably connectedto these, for example via an adhesive strip.

FIG. 4 b shows a filter bracket 11 that overlaps the filter housing 2 inthe area of the slide-in opening 13, wherein a separable connectingmeans 29, such as a multiple-use adhesive film or a Velcro strip, isarranged in the area of overlap.

FIG. 4 c also shows an overlapping arrangement of filter bracket 11 andfilter housing 2, with a connection being produced via a screw 30.

FIG. 4 d shows an embodiment in which the filter bracket 11 rests on across strip 31, which is connected to the filter housing 2. The crossstrip 31 can be configured either as a separate component or as a singlepiece combined with the filter housing 2.

FIG. 4 e shows a solution in which the individual filter elements 10project into the interior of the filter housing 2 through openings 32,and the filter bracket 11 rests on the filter housing 2.

FIG. 4 f shows a non-positive snap connection between the filter bracket11 and the filter housing 2, in which, in the installed position, aspherical locking projection 33 on the filter bracket 11 engages in alocking depression 34 in the filter housing.

FIGS. 4 g through 4 j show examples of the positioning of the filterelements 10 and/or a filter insert 12 in the interior of the filterhousing 2.

FIG. 4 g shows a recess 35, into which a filter bracket 11 of a filterinsert 12 extends. To facilitate insertion, the recess 35 can be angled,which is not shown here.

FIG. 4 h shows a socket-like mount 36, which is arranged on the interiorside of a boundary wall 4. This can be configured to form a single piecewith the boundary wall 4, or as a separate component that is fastened tothe boundary wall 4.

FIG. 4 i shows a positioning pin 37, which extends into a recess at theend surface of the filter element 10 or the filter bracket 11. Thepositioning pin 37 can also have a pointed tip, in which case,especially with relatively soft filter elements, no special recess isrequired.

FIG. 4 j shows a through hole 38 in a boundary wall 4 that serves as theguide element for a filter element 10 and/or a filter bracket 11.

In FIG. 5, various embodiments of filter inserts 12 are shown, each insimplified form, from a frontal view and a plan view.

FIG. 5 a shows a filter insert 12 with a pronounced longitudinal axis39, a vertical axis 40 and a transverse axis 41, comprised of a filterbracket 11 and four filter elements 10 attached thereto and parallel toone another. The filter insert 12 is symmetrical only with reference toa plane spanned by the longitudinal axis 39 and the vertical axis 40.With two filter inserts 12 positioned in tandem according to FIG. 5 a,the offset between filter elements 10 in tandem can be achieved byrotating the filter insert 12 halfway around the vertical axis 40, whichdoes not cause the filter brackets 11 to be offset in relation to oneanother.

FIG. 5 b shows a filter insert 12 with two planes of symmetry, namelythe plane that is spanned by the longitudinal axis 39 and the verticalaxis 40 and the plane that is spanned by the vertical axis 40 and thetransverse axis 41. To achieve an offset between filter elements 10arranged in tandem, filter brackets 11 arranged in tandem must be offsetin relation to one another. The advantage of this embodiment is thatindividual filter inserts 12 can be turned in the filter housing 2 inorder to fully utilize the filtering surfaces on the front and rearsides equally, thereby extending their service life.

FIG. 5 c shows a filter insert 12 with a third plane of symmetry,spanned by the longitudinal axis 39 and the transverse axis 41. Forthis, both ends of the filter elements 10 must be fastened to a filterbracket 11. Two filter brackets 11 of uniform construction, or oneframe-shaped filter bracket 11, can be used for this.

FIG. 6 contains two embodiments of filter elements 10 having rectangularcross-sections, in a simplified, perspective illustration.

FIG. 6 a shows a filter element 10 with a rectangular base. Only asection of the surface of this filter element 10 is provided with thefilter medium 20. In this embodiment, the unattached ends of the filterelement 10 can easily be pressed into a filter bracket 11. With thisasymmetrical embodiment, care must be taken in orienting the filtermedium 20 during assembly.

FIG. 6 b shows a rectangular filter element 10, in which the filtermedium 20 extends around the entire periphery. With this embodiment, afilter insert 12 can be turned in order to extend its service life. Amagnetic element 42 comprised of a permanent magnet is arranged in theinterior of the filter element 10, which increases the collection effectfor ferromagnetic particles in the flow of exhaust air.

FIG. 7 contains two embodiments of filter elements 10 having circularcross-sections, in a simplified, perspective illustration.

FIG. 7 a shows a circular cylindrical filter element 10, which is formedin its entirety from the filter medium 20. The adsorbent fluid is storedwithin the porous filter medium 20, and is largely evenly distributed asa result of the capillary effect. This embodiment can be produced verycost-effectively.

FIG. 7 b shows a circular cylindrical filter element 10, comprising acircular cylindrical container 43 with filter medium 20 arranged on itsouter surface. Said filter medium is fluid-connected to the interior ofthe container 43 via openings 44, such as narrow bore holes or slits.The container 43 serves as a storage vessel for the fluid, which itdelivers to the filter medium 20 through the openings 44 during theperiod of use.

In FIG. 8, a further variant for connecting two filter modules 1 isshown. A clamp element 45 serves as the connecting means, and connectstwo boundary walls 4 of two filter housings 2 or filter modules 1 in anon-positive fashion. The clamp element 45 is configured as a U-shapedprofile, which is placed over two adjacent edges of two boundary walls4. This causes the clamp element 45 to become elastically deformed,effecting the non-positive, friction connection as a result of thecontact force acting between the fastening walls 4. The clamp element 45can be placed on the front side and/or on the rear side of the filterhousing 2. When the clamp connection is used on only one side, adistance between the boundary walls 4 can be adjusted by applying forceto the other side—giving the composite of multiple filter modules acertain flexibility to adjust to uneven machine housings 22.

For the sake of correctness, it is mentioned in closing that for abetter understanding of the structure of the filter module 1, saidmodule and/or its components have been illustrated in part not to scaleand/or enlarged and/or reduced.

The exemplary embodiments show possible variants of the filter module 1,however it is noted here that the invention is not limited to thespecifically represented practical variants; instead, diversecombinations of the individual practical variants are also possible, andthis possibility of variation, based upon the teaching regardingtechnical handling using the objective invention, is within the abilityof one of ordinary skill in this technical field. Therefore allconceivable variants that can be implemented by combining individualdetails of the represented and described variants are included withinthe scope of protection.

Above all, the embodiments shown specifically in FIGS. 1 through 8 canform the object of autonomous, inventive solutions. The objects andsolutions specified in the invention in this respect may be found in thedetailed descriptions of these diagrams.

1. A filter module for removing air-polluting materials from a flow ofmachine exhaust, said filter module comprising: (a) a filter housing;(b) at least two parallel filter groups disposed within the filterhousing, each such filter group having a longitudinal axis and aplurality of spaced-apart rod-shaped filter elements; (c) acenter-to-center distance defined by-at least two or more spaced-apartrod-shaped filter elements of one of such filter groups; (d) at leasttwo filter inserts, each said filter insert formed by the connection ofat least two or more spaced-apart rod-shaped filter elements of one ofsaid filter groups, said filter insert detachably coupling to the filterhousing such as to allow exchanging of single filter insertsindependently from other filter inserts; (e) wherein each of said filtergroups are situated within the filter housing having the longitudinalaxis crosswise to the direction of the flow of exhaust, and (f) whereina first of said filter groups is arranged: (i) in front of a second ofsaid filter groups relative to the direction of flow of exhaust so thatthe exhaust flows through a filter insert of said first filter groupthen through a filter insert of said second filter group, and (ii)offset longitudinally from a second of said filter groups by half of thecenter-to-center distance.
 2. The filter module according to claim 1,wherein the filter housing includes at least one slide-in opening forsliding in the filter insert crosswise to the direction of flow ofexhaust.
 3. The filter module according to claim 1, wherein at least oneguide element is configured on the filter housing for positioning thefilter insert in an installed state.
 4. The filter module according toclaim 2, wherein at least one guide element is formed by the at leastone slide-in opening for positioning the filter insert in an installedstate.
 5. The filter module according to claim 2, wherein at least oneguide element is formed by a recess in the filter housing positionedopposite the at least one slide-in opening.
 6. The filter moduleaccording to claim 1, further comprising guide elements for each of atleast two filter inserts, wherein said guide elements are: (a) situatedin tandem in the direction of the flow of exhaust; and (b) arranged inan offset from one another crosswise to the longitudinal axes of thefilter groups and the direction of flow of exhaust.
 7. The filter moduleaccording to claim 1, wherein within a filter group, a surface area ofthe filter elements in a plane perpendicular to the direction of flowhas a larger surface area than the free passage surface area between thefilter elements in a plane perpendicular to the direction of flow ofexhaust.
 8. The filter module according to claim 1, wherein a pluralityof filter elements are separably connected to a filter bracket.
 9. Thefilter module according to claim 8, wherein the filter elements areconnected to the filter bracket by means of a press fit.
 10. The filtermodule according to claim 1, wherein the filter elements include afilter medium of material selected from the group consisting of porousmaterial, fibrous mesh, pulp material and plastic foam.
 11. The filtermodule according to claim 1, wherein a filter medium is arranged on onlya partial section of at least one filter element.
 12. The filter moduleaccording to claim 1, wherein a filter medium is arranged on a surfaceof at least one filter element.
 13. The filter module according to claim12, wherein the filter medium comprises a fluid selected from the groupconsisting of glycerin, silicone oil, essential oil, paraffin oil andlatex emulsion.
 14. The filter module according to claim 13, wherein thefluid comprises a scent releasing substance.
 15. The filter moduleaccording to claim 13, wherein the fluid comprises a substance selectedfrom the group consisting of an antibacterial, antiviral, antimycoticand fungicidal substance.
 16. The filter module according to claim 13,wherein the fluid is biodegradable.
 17. The filter module according toclaim 12, wherein the filter medium comprises a surface selected fromthe group consisting of an antibacterial, antiviral, antimycotic andfungicidal surface.
 18. The filter module according to claim 1, whereinone or more filter elements have hollow spaces configured to hold fluid,and wherein said hollow spaces are fluid-connected to a filter medium ofthe filter element via one or more openings.
 19. The filter moduleaccording to claim 1, wherein a filter medium of the filter elements isformed at least partially from activated carbon.
 20. The filter moduleaccording to claim 1, wherein one or more filter elements comprise amagnetic component.
 21. The filter module according to claim 1, whereinone or more filter elements have an elongate cross-section.
 22. Thefilter module according to claim 21, wherein each of said filterelements further comprises a longitudinal axis and wherein thelongitudinal axis of the cross-section of one or more of said filterelements is aligned crosswise to the direction of the flow of exhaust.23. The filter module according to claim 1, wherein one or more filterelements have a cross-sectional shape selected from the group consistingof rectangle, square, triangle, circle, star and oval.
 24. The filtermodule according to claim 1, further comprising a groove on a rear sideof the filter housing that (a) faces a machine and (b) is configured tocouple to an element with an angled profile for mounting said filterhousing on the machine.
 25. The filter module according to claim 1,wherein the filter housing includes at least one connecting element forconnecting the filter module to one or more additional filter modules.26. The filter module according to claim 1, further comprising aseparable non-positive snap connection between a filter insert and thefilter housing.
 27. The filter module according to claim 1, wherein thefilter housing further comprises an intake opening and an outlet openingand wherein a covering grid plate is arranged at the outlet opening. 28.The filter module according to claim 1, further comprising a mountingelement configured for connecting to an exhaust selected from the groupconsisting of vehicle interior exhaust, air conditioner exhaust, vacuumexhaust and ventilation exhaust.